MLA

McKay, Claude, 1890-1948. "My Mother," typescript and typescript carbon. Box 12, folder 377. n.d.. https://collections.library.yale.edu/catalog/32268860.

APA, 6th edition

McKay, Claude, 1890-1948. (["Box 12, folder 377"])(n.d.)["My Mother," typescript and typescript carbon]. https://collections.library.yale.edu/catalog/32268860.